This kind of thing has been done with modern bullets, and "Flechettes", and might be possible with a ball made of copper. I don't believe that you could do this successfully with pure lead, and expect the ball to stay together at it spins going through the air. You could not guarantee that the blades of that " propeller would peel back or "Open" uniformly at the same time. The result would be as unstable as an airplane propeller that loses one of its blades. ( It happened all the time in combat in WWII). The ball would literally rip itself apart in flight, with no " sweet spot" down range you could be assured of hitting.
Try shooting a Round Ball out of your rifle, with several pieces of smaller shot pellets in front of it. The larger ball would push right through the smaller pellets, no matter what size you use, sending them into all directions. If you want to shoot a duplex load that stays together somewhat, you put the buckshot down first, and then the large ball next, so that the large ball precedes the smaller buckshot down range, and doesn't interrupt their travel by bumping them out of the way.
While this trial is Not exactly the same as a cut RB, it demonstrates the kind of forces you would have to deal with if you used a cut ball as you describe. Smoothbores, without rifling of any kind, show some slight promise of delivering this kind of ball or ball and buck to a target, simply because they don't spin the projectile.
The initial rotation speed on rifle balls, and bullets is awesome. At 1500 fps, and in a 1:48 ROT barrel, the RB is spinning at the rate of 1,875 revolutions per minute. Now, air resistance begins to slow the speed of rotation as soon as the ball leaves the barrel, so the rotational speed lessens to some degree during flight. If you compare These speeds of rotation to that of a high speed drill, you begin to understand the in-flight problems of controlling the expansion, and accuracy of the kind of projectile you describe.
A PRB is effective in killing game because of its diameter and weight. The larger the caliber, the heavier the ball, and the greater the penetration and damage to internal organs. A pure lead ball happens to expand at even very low velocities on hitting flesh- much more so than any other projectile we have come up with to date.
Even in modern copper jacketed, Hollow Point bullets, the core that does the expansion is still lead. Barnes did a lot of work in the past 50 years trying to create an all copper bullet that delivers the same kind of wound characteristics, and he succeeded better than anyone else. But, those bullets simply don't work in BP guns, and no one has come up with any different design for a PRB that works better, than pure lead.
Hornady now makes a bullet with copper jacket and hollow nose, with a soft plastic nose in it above an open cavity. The shape of the bullet aids in accurate flight, but on impact, the plastic nose is driven back into the cavity and helps the bullet expand in flesh. Something like that might work, with modifications such as you suggest, in a MODERN BULLET, shot from modern guns. However, I just don't see how it could work with a PRB made of lead. :thumbsup:
Paul
